Hakan Sarikaya
University of Zurich
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Hakan Sarikaya.
Neurology | 2009
Dimitrios Georgiadis; Marcel Arnold; H.C. von Buedingen; P. Valko; Hakan Sarikaya; V. Rousson; Heinrich P. Mattle; Marie-Germaine Bousser; Ralf W. Baumgartner
Background: No randomized study has yet compared efficacy and safety of aspirin and anticoagulants in patients with spontaneous dissection of the cervical carotid artery (sICAD). Methods: Prospectively collected data from 298 consecutive patients with sICAD (56% men; mean age 46 ± 10 years) treated with anticoagulants alone (n = 202) or aspirin alone (n = 96) were retrospectively analyzed. Admission diagnosis was ischemic stroke in 165, TIA in 37, retinal ischemia in 8, and local symptoms and signs (headache, neck pain, Horner syndrome, cranial nerve palsy) in 80 patients, while 8 patients were asymptomatic. Clinical follow-up was obtained after 3 months by neurologic examination (97% of patients) or structured telephone interview. Outcome measures were 1) new cerebral ischemic events, defined as ischemic stroke, TIA, or retinal ischemia, 2) symptomatic intracranial hemorrhage, and 3) major extracranial bleeding. Results: During follow-up, ischemic events were rare (ischemic stroke, 0.3%; TIA, 3.4%; retinal ischemia, 1%); their frequency did not significantly differ between patients treated with anticoagulants (5.9%) and those treated with aspirin (2.1%). The same was true for hemorrhagic adverse events (anticoagulants, 2%; aspirin, 1%). New ischemic events were significantly more frequent in patients with ischemic events at onset (6.2%) than in patients with local symptoms or asymptomatic patients (1.1%). Conclusions: Within the limitations of a nonrandomized study, our data suggest that frequency of new cerebral and retinal ischemic events in patients with spontaneous dissection of the cervical carotid artery is low and probably independent of the type of antithrombotic treatment (aspirin or anticoagulants).
Stroke | 2013
Sanne M. Zinkstok; Stefan T. Engelter; Henrik Gensicke; Philippe Lyrer; Peter A. Ringleb; Ville Artto; Jukka Putaala; Elena Haapaniemi; Turgut Tatlisumak; Yaohua Chen; Didier Leys; Hakan Sarikaya; Patrik Michel; Céline Odier; Jörg Berrouschot; Marcel Arnold; Mirjam Rachel Heldner; Andrea Zini; Valentina Fioravanti; Visnja Padjen; Ljiljana Beslac-Bumbasirevic; Alessandro Pezzini; Yvo B.W.E.M. Roos; Paul J. Nederkoorn
Background and Purpose— Intravenous thrombolysis for acute ischemic stroke is beneficial within 4.5 hours of symptom onset, but the effect rapidly decreases over time, necessitating quick diagnostic in-hospital work-up. Initial time strain occasionally results in treatment of patients with an alternate diagnosis (stroke mimics). We investigated whether intravenous thrombolysis is safe in these patients. Methods— In this multicenter observational cohort study containing 5581 consecutive patients treated with intravenous thrombolysis, we determined the frequency and the clinical characteristics of stroke mimics. For safety, we compared the symptomatic intracranial hemorrhage (European Cooperative Acute Stroke Study II [ECASS-II] definition) rate of stroke mimics with ischemic strokes. Results— One hundred stroke mimics were identified, resulting in a frequency of 1.8% (95% confidence interval, 1.5–2.2). Patients with a stroke mimic were younger, more often female, and had fewer risk factors except smoking and previous stroke or transient ischemic attack. The symptomatic intracranial hemorrhage rate in stroke mimics was 1.0% (95% confidence interval, 0.0–5.0) compared with 7.9% (95% confidence interval, 7.2–8.7) in ischemic strokes. Conclusions— In experienced stroke centers, among patients treated with intravenous thrombolysis, only a few had a final diagnosis other than stroke. The complication rate in these stroke mimics was low.
Stroke | 2011
Sanne M. Zinkstok; Mervyn D.I. Vergouwen; Stefan T. Engelter; Philippe Lyrer; Leo H. Bonati; Marcel Arnold; Heinrich P. Mattle; Urs Fischer; Hakan Sarikaya; Ralf W. Baumgartner; Dimitrios Georgiadis; Céline Odier; Patrik Michel; Jukka Putaala; Martin Griebe; Nils Wahlgren; Niaz Ahmed; Nan van Geloven; Rob J. de Haan; Paul J. Nederkoorn
Background and Purpose— The safety and efficacy of thrombolysis in cervical artery dissection (CAD) are controversial. The aim of this meta-analysis was to pool all individual patient data and provide a valid estimate of safety and outcome of thrombolysis in CAD. Methods— We performed a systematic literature search on intravenous and intra-arterial thrombolysis in CAD. We calculated the rates of pooled symptomatic intracranial hemorrhage and mortality and indirectly compared them with matched controls from the Safe Implementation of Thrombolysis in Stroke–International Stroke Thrombolysis Register. We applied multivariate regression models to identify predictors of excellent (modified Rankin Scale=0 to 1) and favorable (modified Rankin Scale=0 to 2) outcome. Results— We obtained individual patient data of 180 patients from 14 retrospective series and 22 case reports. Patients were predominantly female (68%), with a mean±SD age of 46±11 years. Most patients presented with severe stroke (median National Institutes of Health Stroke Scale score=16). Treatment was intravenous thrombolysis in 67% and intra-arterial thrombolysis in 33%. Median follow-up was 3 months. The pooled symptomatic intracranial hemorrhage rate was 3.1% (95% CI, 1.3 to 7.2). Overall mortality was 8.1% (95% CI, 4.9 to 13.2), and 41.0% (95% CI, 31.4 to 51.4) had an excellent outcome. Stroke severity was a strong predictor of outcome. Overlapping confidence intervals of end points indicated no relevant differences with matched controls from the Safe Implementation of Thrombolysis in Stroke–International Stroke Thrombolysis Register. Conclusions— Safety and outcome of thrombolysis in patients with CAD-related stroke appear similar to those for stroke from all causes. Based on our findings, thrombolysis should not be withheld in patients with CAD.
Lancet Neurology | 2015
Stéphanie Debette; Annette Compter; Marc-Antoine Labeyrie; Maarten Uyttenboogaart; T. M. Metso; Jennifer J. Majersik; Barbara Goeggel-Simonetti; S. T. Engelter; Alessandro Pezzini; Philippe Bijlenga; Andrew M. Southerland; O. Naggara; Yannick Béjot; John W. Cole; Anne Ducros; Giacomo Giacalone; Sabrina Schilling; Peggy Reiner; Hakan Sarikaya; Janna C Welleweerd; L. Jaap Kappelle; Gert Jan de Borst; Leo H. Bonati; Simon Jung; Vincent Thijs; Juan Jose Martin; Tobias Brandt; Caspar Grond-Ginsbach; Manja Kloss; Tohru Mizutani
Spontaneous intracranial artery dissection is an uncommon and probably underdiagnosed cause of stroke that is defined by the occurrence of a haematoma in the wall of an intracranial artery. Patients can present with headache, ischaemic stroke, subarachnoid haemorrhage, or symptoms associated with mass effect, mostly on the brainstem. Although intracranial artery dissection is less common than cervical artery dissection in adults of European ethnic origin, intracranial artery dissection is reportedly more common in children and in Asian populations. Risk factors and mechanisms are poorly understood, and diagnosis is challenging because characteristic imaging features can be difficult to detect in view of the small size of intracranial arteries. Therefore, multimodal follow-up imaging is often needed to confirm the diagnosis. Treatment of intracranial artery dissections is empirical in the absence of data from randomised controlled trials. Most patients with subarachnoid haemorrhage undergo surgical or endovascular treatment to prevent rebleeding, whereas patients with intracranial artery dissection and cerebral ischaemia are treated with antithrombotics. Prognosis seems worse in patients with subarachnoid haemorrhage than in those without.
Stroke | 2009
Stefan T. Engelter; Matthieu P. Rutgers; Florian Hatz; Dimitrios Georgiadis; Felix Fluri; Lucka Sekoranja; Guido Schwegler; Felix Müller; Bruno Weder; Hakan Sarikaya; Regina Luthy; Marcel Arnold; Krassen Nedeltchev; Marc Reichhart; Heinrich P. Mattle; Barbara Tettenborn; Hansjörg Hungerbühler; Roman Sztajzel; Ralf W. Baumgartner; Patrick Michel; Philippe Lyrer
Background and Purpose— Intravenous thrombolysis (IVT) for stroke seems to be beneficial independent of the underlying etiology. Whether this is also true for cervical artery dissection (CAD) is addressed in this study. Methods— We used the Swiss IVT databank to compare outcome and complications of IVT-treated patients with CAD with IVT-treated patients with other etiologies (non-CAD patients). Main outcome and complication measures were favorable 3-month outcome, intracranial cerebral hemorrhage, and recurrent ischemic stroke. Modified Rankin Scale score ≤1 at 3 months was considered favorable. Results— Fifty-five (5.2%) of 1062 IVT-treated patients had CAD. Patients with CAD were younger (median age 50 versus 70 years) but had similar median National Institutes of Health Stroke Scale scores (14 versus 13) and time to treatment (152.5 versus 156 minutes) as non-CAD patients. In the CAD group, 36% (20 of 55) had a favorable 3-month outcome compared with 44% (447 of 1007) non-CAD patients (OR, 0.72; 95% CI, 0.41 to 1.26), which was less favorable after adjustment for age, gender, and National Institutes of Health Stroke Scale score (OR, 0.50; 95% CI, 0.27 to 0.95; P=0.03). Intracranial cerebral hemorrhages (asymptomatic, symptomatic, fatal) were equally frequent in CAD (14% [7%, 7%, 2%]) and non-CAD patients (14% [9%, 5%, 2%]; P=0.99). Recurrent ischemic stroke occurred in 1.8% of patients with CAD and in 3.7% of non-CAD-patients (P=0.71). Conclusion— IVT-treated patients with CAD do not recover as well as IVT-treated non-CAD patients. However, intracranial bleedings and recurrent ischemic strokes were equally frequent in both groups. They do not account for different outcomes and indicate that IVT should not be excluded in patients who may have CAD. Hemodynamic compromise or frequent tandem occlusions might explain the less favorable outcome of patients with CAD.
Stroke | 2009
Krassen Nedeltchev; Stefan Bickel; Marcel Arnold; Hakan Sarikaya; Dimitrios Georgiadis; Matthias Sturzenegger; Heinrich P. Mattle; Ralf W. Baumgartner
Background and Purpose— We set out to investigate the predictors and time course for recanalization of spontaneous dissection of the cervical internal carotid artery (SICAD). Methods— We prospectively included 249 consecutive patients (mean age, 45±11 years) with 268 SICAD. Ultrasound examinations were performed at presentation, during the first month, and then at 3, 6, and 12 months, and clinical follow-ups after 3, 6, and 12 months. Results— Of 268 SICADs, 20 (7.5%) presented with ≤50% stenosis, 31 (11.6%) with 51% to 80% stenosis, 92 (34.3%) with 81% to 99% stenosis, and 125 (46.6%) with an occlusion. Antithrombotic treatment included anticoagulation in 174 (67%) patients, aspirin in 64 (24%) patients, and aspirin followed by anticoagulation or vice versa in 22 (8%) patients. Follow-up ultrasound showed normal findings in 160 (60%), ≤50% stenosis in 27 (10%), 51% to 80% stenosis in 4 (1%), 81% to 99% stenosis in 26 (10%), and occlusion in 51 (19%) vessels. The rate of complete recanalization was 16% at 1 month, 50% at 3 months, and 60% at 6 and 12 months. Initial occlusion of the dissected vessels reduced the odds of recanalization (OR, 4.0; 95% CI, 2.2–7.3; P<0.001), whereas the occurrence of local symptoms and signs only at presentation were independently associated with complete recanalization (OR, 0.4; 95% CI, 0.2–0.8; P=0.048). Conclusions— These results suggest that recanalization of SICAD occurs mainly within the first 6 months after the onset of symptoms. Initial occlusion reduces the likelihood of complete recanalization, whereas presentation with local symptoms and signs only increases it.
Neurology | 2011
S. T. Engelter; Lauri Soinne; Peter A. Ringleb; Hakan Sarikaya; Régis Bordet; Jörg Berrouschot; Céline Odier; Marcel Arnold; Gary A. Ford; Alessandro Pezzini; Andrea Zini; K. Rantanen; Andrea Rocco; Leo H. Bonati; L. Kellert; Daniel Strbian; A. Stoll; Niklaus Meier; Patrik Michel; R. W. Baumgartner; Didier Leys; Turgut Tatlisumak; P. A. Lyrer
Objective: To examine whether prior statin use affects outcome and intracranial hemorrhage (ICH) rates in stroke patients receiving IV thrombolysis (IVT). Methods: In a pooled observational study of 11 IVT databases, we compared outcomes between statin users and nonusers. Outcome measures were excellent 3-month outcome (modified Rankin scale 0–1) and ICH in 3 categories. We distinguished all ICHs (ICHall), symptomatic ICH based on the criteria of the ECASS-II trial (SICHECASS-II), and symptomatic ICH based on the criteria of the National Institute of Neurological Disorders and Stroke (NINDS) trial (SICHNINDS). Unadjusted and adjusted odds ratios (OR) with 95% confidence intervals were calculated. Results: Among 4,012 IVT-treated patients, 918 (22.9%) were statin users. They were older, more often male, and more frequently had hypertension, hypercholesterolemia, diabetes, coronary heart disease, and concomitant antithrombotic use compared with nonusers. Fewer statin users (35.5%) than nonusers (39.7%) reached an excellent 3-month outcome (ORunadjusted 0.84 [0.72–0.98], p = 0.02). After adjustment for age, gender, blood pressure, time to thrombolysis, and stroke severity, the association was no longer significant (0.89 [0.74–1.06], p = 0.20). ICH occurred by trend more often in statin users (ICHall 20.1% vs 17.4%; SICHNINDS 9.2% vs 7.5%; SICHECASS-II 6.9% vs 5.1%). This difference was statistically significant only for SICHECASS-II (OR = 1.38 [1.02–1.87]). After adjustment for age, gender, blood pressure, use of antithrombotics, and stroke severity, the ORadjusted for each category of ICH (ICHall 1.15 [0.93–1.41]; SICHECASS-II 1.32 [0.94–1.85]; SICHNINDS 1.16 [0.87–1.56]) showed no difference between statin users and nonusers. Conclusion: In stroke patients receiving IVT, prior statin use was neither an independent predictor of functional outcome nor ICH. It may be considered as an indicator of baseline characteristics that are associated with a less favorable course.
Stroke | 2013
Michelle von Babo; Gian Marco De Marchis; Hakan Sarikaya; Christian Stapf; Frédérique Buffon; Urs Fischer; Mirjam Rachel Heldner; Jan Gralla; Simon Jung; Barbara Goeggel Simonetti; Heinrich P. Mattle; Ralf W. Baumgartner; Marie-Germaine Bousser; Marcel Arnold
Background and Purpose— To compare potential risk factors, clinical symptoms, diagnostic delay, and 3-month outcome between spontaneous internal carotid artery dissection (sICAD) and spontaneous vertebral artery dissection (sVAD). Methods— We compared patients with sICAD (n=668) and sVAD (n=302) treated in 3 university hospitals. Results— Patients with sICAD were older (46.3±9.6 versus 42.0±10.2 years; P<0.001), more often men (62.7% versus 53.0%; P=0.004), and presented more frequently with tinnitus (10.9% versus 3.4%; P<0.001) and more severe ischemic strokes (median National Institutes of Health Stroke Scale, 10±7.1 versus 5±5.9; P<0.001). Patients with sVAD had more often bilateral dissections (15.2% versus 7.6%; P<0.001) and were more often smokers (36.0% versus 28.7%; P=0.007). Thunderclap headache (9.2% versus 3.6%; P=0.001) and neck pain were more common (65.8% versus 33.5%; P<0.001) in sVAD. Subarachnoid hemorrhage (6.0% versus 0.6%; P<0.001) and ischemic stroke (69.5% versus 52.2%; P<0.001) were more frequent in sVAD. After multivariate analysis, sex difference lost its significance (P=0.21), and all other variables remained significant. Time to diagnosis was similar in sICAD and sVAD and improved between 2001 and 2012 compared with the previous 10-year period (8.0±10.5 days versus 10.7±13.2 days; P=0.004). In sVAD, favorable outcome 3 months after ischemic stroke (modified Rankin Scale, 0–2: 88.8% versus 58.4%; P<0.001), recurrent transient ischemic attack (4.8% versus 1.1%; P=0.001), and recurrent ischemic stroke (2.8% versus 0.7%; P=0.02) within 3 months were more frequent. Conclusions— sICAD and sVAD patients differ in many aspects. Future studies should perform separate analyses of these 2 entities.
Stroke | 2010
Marcel Arnold; Rebekka Kurmann; Aekaterini Galimanis; Hakan Sarikaya; Christian Stapf; Jan Gralla; Dimitrios Georgiadis; Urs Fischer; Heinrich P. Mattle; Marie-Germaine Bousser; Ralf W. Baumgartner
Background and Purpose— Spontaneous vertebral artery dissection (sVADs) mainly cause cerebral ischemia, with or without associated local symptoms and signs (headache, neck pain, or cervical radiculopathy), or with local symptoms and signs only. Methods— We compared the presenting characteristics of consecutive patients with single sVADs and ischemic events and those with local symptoms and signs only. Results— Of the 186 patients with first-ever unilateral sVAD, 165 (89%) presented with cerebral ischemia, and 21 (11%) presented with local symptoms and signs only. Patients with sVAD and ischemia were more often male (63% vs 29%; P=0.002), older (mean±SD age, 43.6±9.9 vs 38.6±9.0 years; P=0.027), and smokers (14% vs 3%; P=0.010), but less often, they had a history of migraine without aura (17% vs 38%; P=0.025) than did patients without ischemia. The multivariate analysis confirmed independent associations between male sex (P=0.024), increasing age (0.027), and smoking (P=0.012) and sVADs causing cerebral ischemia. Conclusions— These results suggest that men, older patients, and smokers with sVADs may be at increased risk for ischemic events.
Neurology | 2013
Henrik Gensicke; Sanne M. Zinkstok; Yvo B.W.E.M. Roos; David J. Seiffge; Peter A. Ringleb; Ville Artto; Jukka Putaala; Elena Haapaniemi; Didier Leys; Régis Bordet; Patrik Michel; Céline Odier; Jörg Berrouschot; Marcel Arnold; Mirjam Rachel Heldner; Andrea Zini; Guido Bigliardi; Visnja Padjen; Nils Peters; Alessandro Pezzini; Christian Schindler; Hakan Sarikaya; Leo H. Bonati; Turgut Tatlisumak; Philippe Lyrer; Paul J. Nederkoorn; Stefan T. Engelter
Objective: To investigate the association of renal impairment on functional outcome and complications in stroke patients treated with IV thrombolysis (IVT). Methods: In this observational study, we compared the estimated glomerular filtration rate (GFR) with poor 3-month outcome (modified Rankin Scale scores 3–6), death, and symptomatic intracranial hemorrhage (sICH) based on the criteria of the European Cooperative Acute Stroke Study II trial. Unadjusted and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Patients without IVT treatment served as a comparison group. Results: Among 4,780 IVT-treated patients, 1,217 (25.5%) had a low GFR (<60 mL/min/1.73 m2). A GFR decrease by 10 mL/min/1.73 m2 increased the risk of poor outcome (OR [95% CI]): (ORunadjusted 1.20 [1.17–1.24]; ORadjusted 1.05 [1.01–1.09]), death (ORunadjusted 1.33 [1.28–1.38]; ORadjusted 1.18 [1.11–1.249]), and sICH (ORunadjusted 1.15 [1.01–1.22]; ORadjusted 1.11 [1.04–1.20]). Low GFR was independently associated with poor 3-month outcome (ORadjusted 1.32 [1.10–1.58]), death (ORadjusted 1.73 [1.39–2.14]), and sICH (ORadjusted 1.64 [1.21–2.23]) compared with normal GFR (60–120 mL/min/1.73 m2). Low GFR (ORadjusted 1.64 [1.21–2.23]) and stroke severity (ORadjusted 1.05 [1.03–1.07]) independently determined sICH. Compared with patients who did not receive IVT, treatment with IVT in patients with low GFR was associated with poor outcome (ORadjusted 1.79 [1.41–2.25]), and with favorable outcome in those with normal GFR (ORadjusted 0.77 [0.63–0.94]). Conclusion: Renal function significantly modified outcome and complication rates in IVT-treated stroke patients. Lower GFR might be a better risk indicator for sICH than age. A decrease of GFR by 10 mL/min/1.73 m2 seems to have a similar impact on the risk of death or sICH as a 1-point-higher NIH Stroke Scale score measuring stroke severity.